Changes in the Chemical Composition of Polyethylene Terephthalate Under UV Radiation in Various Environmental Conditions

Published

August 8, 2024

Author(s)

Li Piin Sung, Rachel Cook, Chunlei Fan, YueJin Li, Sara Rostampour

Abstract

Polyethylene terephthalate has been widely used in the packaging industry. Degraded PET micro(nano)plastics could pose public health concerns following release into various environments. This study focuses on PET degradation under ultraviolet radiation using the NIST SPHERE facility at the National Institute of Standards and Technology in saturated humidity (i.e., ≥95% relative humidity) and dry conditions (i.e., ≤5% relative humidity) with varying temperatures (30 ◦C, 40 ◦C, and 50 ◦C) for up 20 days. ATR-FTIR was used to characterize the chemical composition change of degraded PET as a function of UV exposure time. The results showed that the cleavage of the ester bond at peak 1713 cm−1 and the formation of the carboxylic acid at peak 1685 cm−1 were significantly influenced by UV radiation. Furthermore, the formation of carboxylic acid was considerably higher at saturated humidity and 50 ◦C conditions compared with dry conditions. The ester bond cleavage was also more pronounced in saturated humidity conditions. The novelty of this study is to provide insights into the chemical degradation of PET under environmental conditions, including UV radiation, humidity, and temperature. The results can be used to develop strategies to reduce the environmental impact of plastic pollution.

Citation

Polymers

Pub Type

Journals

Download Paper

https://doi.org/10.3390/polym16162249

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Keywords

chemical change, degradation, Fourier transform infrared spectrometry (FTIR), NIST SPHERE, microplastics (MPs), polyethylene terephthalate (PET)

Citation

Sung, L. , Cook, R. , Fan, C. , Li, Y. and Rostampour, S. (2024), Changes in the Chemical Composition of Polyethylene Terephthalate Under UV Radiation in Various Environmental Conditions, Polymers, [online], https://doi.org/10.3390/polym16162249, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=957731 (Accessed January 17, 2025)